package com.hxx.service;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.hxx.entity.User;
import com.hxx.util.JDBCComon;

public class UserService {
    JDBCComon jdbc=new JDBCComon();
    //登录
    public User login(String name,String pwd){
        User user=null;
        try {
            Connection conn=jdbc.getConnection();
            Statement st=conn.createStatement();
            String sql="select * from user where  name='"+name+"' and pwd='"+pwd+"'";
            System.out.println("sql--->"+sql);
            ResultSet rss=st.executeQuery(sql);
            //rss.next()只要 结果集合里，至少有一条记录，next方法就会返回true
            if(rss.next()){
                user=new User();
                user.setId(rss.getString("id"));
                user.setName(rss.getString("name"));
            }
            //从下往上关
            rss.close();
            st.close();
            conn.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return user;
    }

    //验证用户名是否存在
    public User checkName(String name){
        User user=null;
        try {
            Connection conn=jdbc.getConnection();
            Statement st=conn.createStatement();
            String sql="select * from user where  name='"+name+"' ";
            System.out.println("sql--->"+sql);
            ResultSet rss=st.executeQuery(sql);
            //rss.next()只要 结果集合里，至少有一条记录，next方法就会返回true
            if(rss.next()){
                user=new User();
                user.setId(rss.getString("id"));
                user.setName(rss.getString("name"));
            }
            //从下往上关
            rss.close();
            st.close();
            conn.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return user;
    }


    public List<User> selectAll(){
        List<User> ulist=new ArrayList();
        try {
            Connection conn=jdbc.getConnection();
            Statement st=conn.createStatement();
            String sql="select * from user ";
            System.out.println("sql--->"+sql);
            ResultSet rss=st.executeQuery(sql);
            //rss.next()只要 结果集合里，至少有一条记录，next方法就会返回true
            while(rss.next()){
                User user=new User();
                user.setId(rss.getString("id"));
                user.setName(rss.getString("name"));
                user.setAge(rss.getInt("age"));
                ulist.add(user);
            }
            //从下往上关
            jdbc.closeDB(rss,st,conn);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return ulist;
    }
}
